TABLE OF CONTENTS. XI 



Page. 



Key to the Species and Subspecies of Oorvus 257 



1. Corvus corax prirn'ipalis Eidgway 259 



2. Corvus corax slnuatus ( Wagler) 262 



3. Corvus corax clarionensis Rothschild and Hartert 264 



4. Corvus cryptoleucus Couch 265 



5. Corvus americanus americanus Audubon 267 



6. Corvus americanus pascuus Coues 269 



7. Corvus americanus hesperia Ridgway 270 



8. Corvus americanus caurinus (Baird) 272 



9. Corvus ossifragus Wilson 273 



10. Corvus mexicanus Gmelin '. 275 



11. Corvus pahnarum Wiirttemberg 276 



12. Corvus minutus Gundlach 276 



13. Corvus jamaicensis Gmelin 277 



14. Corvus nasicus Temminck 278 



15. Corvus leucognaphalus leucognaphalus Daudin 278 



. 16. Corvus leucognaphalus erythrophthalmus (Wiirttemberg) 279 



Genus 2. Nucifraga Brisson 280 



Key to the Species of Nucifraga 280 



17. Nucifraga columbiana (Wilson) 281 



Genus 3. Cyanocephalus Bonaparte 283 



18. Cyanocephalus cyanocephalus (Maximilian) 284 



Genus 4. Pica Brisson 286 



Key to the Species of Pica 287 



19. Pica pica hudsonia (Sabine) •- 287 



20. Pica nuttalli Audubon 291 



Genus 5. Calocitta Gray 292 



Key to the Species and Subspecies of Calocitta 293 



21. Calocitta coUiei (Vigors) 294 



22. Calocitta formosa formosa (Swainson) 295 



23. Calocitta formosa azurea Nelson 296 



Genus 6. Psilorhinus Riippell 298 



Key to the Species and Subspecies of Psilorhinus 298 



24. Psilorhinus morio morio (Wagler) 299 



25. Psilorhinus morio fuliginosus (Lesson) 300 



26. Psilorhinus mexicanus mexicanus Ruppell 301 



27. Psilorhinus mexicanus cyanogenys ( Sharpe) 301 



28. Psilorhinus mexicanus vociferus (Cabot) 303 



Genus 7. Cyanocorax Boie 303 



29. Cyanocorax afHnis zeledoni Ridgway 304 



Genus 8. Xanthoura Bonaparte 305 



Key to the Species and Subspecies of Xanthoura 305 



' 30. Xanthoura luxuosa Inxuosa (Lesson) 306 



31. Xanthoura luxuosa glauceacens Eidgway 308 



32. Xanthoura luxuosa vivida Ridgway 309 



33. Xauthoura luxuosa guatimalensis (Bonaparte) 310 



34. Xauthoura luxuosa speciosa Nelson 311 



Genus 9. Cissilopha Bonaparte 312 



Key to Species and Subspecies of Cissilopha 313 



35. Cissilopha san-blasiana san-blasiana ("Vigors) - 313 



36. Cissilopha san-blasiana pulchra Nelson 314 



37. Cissilopha yucatanica (Dubois) 315 



38. Cissilopha beecheii (Vigors) 316 



39. Cissilopha melanocyanea (Hartlaub) 317 



